An example of a prior art mounting means is described in U.S. Pat. No. 4,697,455. In this reference, a coil is mounted to a proof mass assembly by a mounting system that comprises at least three mounting means. Each mounting means has first and second ends and a resilient intermediate portion. This device has the first end of each mounting means connected to the coil and the second end is connected to the proof mass assembly. The intermediate portion provides a low resistance to radial movement between the coil and proof mass assembly but provides a high resistance to movement perpendicular to the radial direction. This invention teaches constructing the piece of the proof mass to which the intermediate portion is attached out of fused quartz like the base of the mounting system.
U.S. Pat. No. 4,400,979 teaches a flexure for hingedly or translationally connecting a force sensing element to a mounting base. The force sensing element, or force sensing transducer, can be used as an accelerometer. The flexure includes one or more recessed surfaces which are substantially coincident with the neutral bending plane of the flexure. An electrically conductive coating on the recessed surfaces of the flexure provides connection to components on the force sensitive element.
In U.S. Pat. No. 4,779,463, flexures are disclosed which support a pendulum assembly of a servo type accelerometer. This reference teaches a way of preventing the flexures from being placed in a state of compression when the pendulum is subjected to acceleration forces directed along the axis of the pendulum normal to the pivotal axis.
At least one pliant member used as a mounting means for high performance transducers, such as accelerometers, is disclosed in U.S. Pat. No. 4,592,234. According to this reference, a transducer assembly comprises a proof mass, including a mass element suspended from a support member and a stator means for supporting the proof mass. A mounting means mounts the proof mass with the stator. The pliant member(s) is (are) positioned to provide the mechanical connection between adjacent points on the proof mass and stator. The axis of pliancy between the proof mass and sector is such that it provides strain relief.
U.S. Pat. No. 4,414,848 teaches a magnetic suspension system which provides constraint for the proof mass in three degrees of freedom. An elastic suspension system provides constraint in three additional degrees of freedom for the proof mass. The elastic suspension is a fine filament array in the preferred embodiment.
These inventions, although they successfully mount a sensor capsule, do not deal with the problem of different temperature coefficients of the sensor and the housing to which the sensor is mounted. Previously known accelerometer sensors were not constructed of silicon, rather the sensors were constructed of a material such as titanium which had a temperature coefficient very close to that of the housing. Because silicon has a much lower temperature coefficient than does the housing material, a new method of mounting was necessary to overcome this problem.
An Integrated Silicon Accelerometer such as that disclosed in U.S. Pat. No. 4,498,342 is a precision instrument developed for applications such as aircraft or missile navigation. The teachings of commonly assigned U.S. Pat. Nos. 4,498,342 and 4,448,445 are hereby incorporated by reference.